Self assessment query

I have nearly 20k owed in tax but I need to complete self assessment from 2014 and 2015 but it won’t allow me to do this online, was hoping someone could advise what I would need to do. Do I need to request 2x sa200 forms any help is greatly appreciated

Hi Iiam Shotton,
As these tax years are out of date, please contact us by webchat or phone here:
Self Assessment: general enquiries
We can advise your further, and issue tax returns to you if necessary.
Thank you. 

I have tried and it advises no agents available I was told to send them in by paper but I still have no idea what I need to do they are more than 4 years old

Hi,

If you are unable to contact us by phone or webchat, you can write to us at the postal address provided in the link below. We can send you the Self Assessment returns for you to complete for the years required. We will also include guidance on how to complete your returns.

Self Assessment: general enquiries

Thank you.