Repeat a year for PGT at Royal Holloway

I have been informed that my 2 courses had failed. Therefore I was offered to resit them again. However, Royal Holloway only permit 40 credits overall to be resat, and I have 50 credits (for 2 courses) so 1 of them was refused to be resat this summer vacation. I have emailed my department about this issue but they haven't answered me yet. So, I'd like to ask you guys that in my situation, will I have to repeat a year? Do I have to study for another year because of 1 failed course? Has anyone been in this likely situation before (especially at RHUL)? Please give me some advises as I'm really worried now. Thank you very much!