eurovox ex500 pvr

Hi Can anyone help

I dont really understand these boxes, like everyone else in the UK mine went off last week and I gor it woeking again on Sunday by using fix codes from internet only for it to be scrambled again 5 hours later.

Would anyone be able to help me or advise me as to what I can do next, I have tried lots of codes and they are not working.

Am in liverpool and with VM, origionally (tw), all help sent is appreciated, I think the provider code is 5a 01

Thanks