Four years on from when we first reported that eBay's user protection systems were failing some of its users, Telegraph Money's postbag continues to receive complaints about the online auction site's money back guarantee policy.

The scheme, which launched in 2013, promises to refund the buyer with the cost of an item if it does not arrive or is not as described. If such a refund is made the seller has the money deducted from their account.

EBay says the guarantee ensures buyers can shop "hassle-free" and in the knowledge that they will receive the item they purchased or their money back.

But many readers have reported being left out of pocket as a result of eBay’s "favourable" stance towards buyers.

In 2014, Telegraph Money spoke to Matthew Wright who lost £160 and was locked out of eBay after he sold a phone to a buyer in Hungary who claimed he didn’t receive it. This resulted in eBay automatically refunding the buyer under the guarantee scheme and passing the cost back to Mr Wright, without investigating the matter.

We also reported on Helen Hickman who encountered a troublesome buyer after selling a brand-new, sealed pushchair for £199.99. The buyer asked to return the item nine days later because she "didn’t need it any more". This was within the 14-day period during which a buyer can receive a refund – provided that the goods were in the same condition as when sold.