When you get promised one rate and charged another, it’s frustrating. When it happens to thousands of customers getting service from the same company all at once, it’s probably a sign of a systematic problem. And one report now says thousands of AT&T and DirecTV customers have been complaining about exactly that for years.

When CBS News went digging, it found more than 4,000 complaints against AT&T and DirecTV (the two merged in 2015) over the last two years relating to overcharges, deals, and promotional pricing gone awry.

CBS highlights two customers’ experiences in particular. The first signed up for a $99.99 promotion — and then the next bill he got was for nearly twice that amount.

When he complained, he said, “As I am talking to them, I get on the internet and I look at the special,” he told CBS News. “Their special is $99.99 and I say, ‘can you just look at the internet?'”

Unfortunately, CBS doesn’t show the his bill in full, but you can certainly see the rate jump. His July, 2016 amount due and payment were $106.46; his August, 2016 amount due is $179.19.

The other customer CBS featured was a Florida woman who shared recordings of her hours-long attempt to get a straight answer out of AT&T over the high rates she was being charged.

“I keep getting bills for $79.49 and my contract says I was only going to pay $24.99 for two years,” she says.

One AT&T customer service representative replies, “There’s some specials on discounts that I’m thinking was actually being removed in error. Your bills are no longer combined. It wasn’t done on our end — it was done on your end.”

Later, another says, “The pricing you were getting was because you were a new customer with the services, now you are an existing customer.”

But, the woman points out, she’d signed a two-year agreement — and the rate change came before her two years were up.

It’s not clear with either customer from CBS’s report how much of the jump in their bills was due to an increase in their base rate, and how much was an increase or change in fees or add-on charges.

When we looked at a real customer’s DirecTV bill last year, we found that more than 20% of it — $53.20 out of a $254 monthly bill — came from additional surcharges and fees. And when we looked at a different customer’s AT&T Uverse bill, $31.05 of their $191.05 charge — about 16% — came from add-ons outside of the stated bundle price.

We also found earlier this year that some of the supposed explanations for DirecTV’s add-on fees made no sense whatsoever. The “regional sports fee” it appends to customers’ bills, ranging from $0 to $7.29 a month, varied wildly from one ZIP code to the next. So one DirecTV customer could be paying as much as $87/year more for than their neighbor across the street for identical service.

After we reported on the issue, AT&T and DirecTV agreed the pricing was in error and promised to credit affected customers the difference.

CBS also points out that AT&T is among the many, many companies that don’t let you sue them, instead requiring you take complaints through mandatory binding arbitration.

AT&T had nearly 150 million customers over the past two years, CBS points out (presumably including all its wireless subscribers). And out of those, 18 (0.000012%, if you feel like doing that math) went through the arbitration process.

Nor can wronged customers band together and file a single class action suit, because the arbitration clauses in contracts ban that, too.

“In my experience, when a large company has a lot of consumers coming forward and saying we feel like we were bait and switched. We were promised one thing and then we got something else. The company knows about it,” consumer advocate and attorney Paul Bland explained to CBS. “So it turns out to be a license to steal.”

Editor's Note: This article originally appeared on Consumerist.