Hb1ac gone up in space of a week

They were probably just looking for confirmation blood samples vary a bit so in reality there is probably no change yet.
HbA1c in theory spans a 3 month period in reality it is most heavily influenced by the 3 to 4 weeks preceding test. The monthly average blood glucose from you meter can be a useful predictor of HbA1c results, not 100% accurate but it should give a ballpark figure.

I wouldn't take much notice of the fasting tests. In fact the HBA1c is no longer a fasting test partly because the fasting blood measure (not the HBA1C) is of little relevance. The HBA1C result is bound to vary so I would ignore the change this time round?

I had borderline results too so my GP ordered a fasting glucose tolerance and that gave me the diagnosis of pre-diabetes. Although at the time I was annoyed and confused about why a third test was necessary, I'm pleased she took the time because it seems that by triangulating those three it gave a more confident diagnosis. Might be worth asking for that?