As a songwriter & former PRS member I'm sorry you feel so badly about this issue.
As a writer who has seen one of his songs taken to concert venues all over the country by a certain famous duo and used to close their act without even an acknowledgement let alone a contribution, and has seen one of his songs used to title track an album by a successful group without an acknowledgement or a contribution, you may understand that I feel differently.
I don't know if its still the case, but PRS used to get members to give them a signed authority to collect what PRS thought appropriate for any use of the material. That means that (in theory) they could ask a million for a performance. A certain hairdresser, who I will not name, was asked some years ago to pay an annual licence for playing a radio in his shop to his customers -- i.e.providing his customers with a service consisting largely of other people's copyright work. He refused and appeared in the local press announcing that he was not going to pay to play HIS radio to HIS customers in HIS shop. PRS, withdrew the request for a cheap annual radio playing licence and substituted a humungous bill. The hairdresser shut up and paid up.
Keep singing, but spare a thought for the fact that songs don't grow on trees.