KCL international foundation

I've applied to kcl for an undergraduate degree, I met the requirements but got rejected. I'm now thinking of applying to the international foundation using my local certificate, I applied with IB for the undergraduate degree but it isn't acceptable for the foundation. I called them to ask if its allowed and they didn't really give me a clear answer and just kept going around the question. Could I be rejected for being "overqualified" ? My local certificate meets the requirement for the foundation. Calling/emailing them seems useless at this point