Challenge Late Tax Return fees accumulated over years without contact from HMRC

Hi,

Prior to becoming a student i was registered as self employed. When i became a student i was told i don't need to do anything else so i didn't stop the self employment. Throughout my studies i never worked or got contacted by HMRC. Last year i got contacted that i own £3600 for late tax returns for 3 years. I hired 2 different accountants to look at the case - both of them charged me money and lied to me - i doubt they even contacted HMRC. I've been told HMRC will change my tax code to collect what i "owe" them.

If anyone can help with this or is willing to advise me please get in touch.