The clock is ticking for Verizon and Sprint customers to apply for their share of a $158 million dollar refund.

If you have or have had service with either mobile carrier at any point since July 2010, you are eligible to apply.

The Federal Communications Commission reached an agreement with both wireless carriers after they were investigated for “cramming ,” or charging customers without their knowledge or permission for premium third-party text messaging services for things like horoscopes, sports scores, flirting tips, celebrity gossip, and so on.

Customers were typically charged about $10 per month for the unwanted services, which were buried in their bills.

AT&T and T-Mobile were part of a similar settlement last year but the deadline has passed for refunds from those carriers.

Verizon has agreed to refund $90 million to customers, while Sprint is paying back $68 million.

How much you’ll get back depends mostly on how many people request refunds.

As part of the agreement, from now on, Verizon and Sprint must get your permission before placing extra charges on your bill.

They must also provide a free service to block third party charges from your account.

To claim the refund, customers must file a claim on the refund websites – click here for Sprint or Verizon.

But you must act fast – the deadline is this Thursday, Dec. 31.