I called Sig yesterday (Monday) and i explained the problem to them. The guy i talked to was real helpful he told me how to repair it and said that it is a common problem usually as a result of a crash and that it was an easy repair. I also told him that the arf was new and i did not want to repair a plane that has never been in the air. he told me he was new to the company and asked me to hold, after about 1 minute he came back and said he would send a new fin (vertical stab) out free of charge. he also read the manual and agreed that the step i made the mistake with was not clear or mentioned in the manual. he also told me that if i ever need advice for repairs or any other help then just call them and they will help.
I have to say Sig has great customer service and will go the extra mile to make sure you are happy and back in the air as soon as possible. I would like to say well done to Sig and hope they keep up the good work