Previous higher education = problem getting 3 years funding! HELP PLEASE

I'm currently in my second year of my degree, my first year was paid for, my second year paid for and I've had a statement stating that I will receive full payment for my 3rd and final year.
I have recently been issued an invoice from my university stating student finance want me to pay back my first year tuition fee.
I believe this has something to do with them only paying for a maximum of 4 years higher education. Before I started uni I completed a 2 year part time HNC course whilst I was an apprentice.
My HNC was higher education and 2 years long so through their calculation I'd only receive 2 years funding for my degree. BUT....

1.) My HNC was paid by employer and had nothing to do with student finance.

2.) They had already agreed my first, second and now third year grants, loans and tuition fees, so are they allowed to just lead me on to think it's all getting paid then suddenly say no??

Help please if anyone else had been in this situation??

Thanks

They count previous years of education regardless of whether they paid for them or not, but it seems like the HNC should have counted for 1 years study (was it 60 credits you did a year for it?).

Yes 60 credits in year 1
65 credits in year 2

Have you been in this situation?

If thats an extra 5 credits in year 2 that could be causing the problem. No but i've had part years which sfe have counted as full ones despite them not paying the tuition fees.

Ah right. Is there any legislation that states how many part time credits = 1 years full time study as I need something to try and shift the part time study to a single year full time so I can pay my tuition fee or I'll be off the course "/