Problems with the lab

I took my son to Spec Savers Northgate in December for eye test and glasses, picked up his glasses and sunglasses on the 7th January. On the 28th January I took his glasses back because the lenses we not in the frame properly, in both his glasses and sunglasses. It is now the 14 February and the glasses are still not back from the lab, the very friendly consultants have told me they couldn't be repaired and had to re-do them....how does this take 3 weeks?? Now either they never went to the lab when they should have, or they have just been forgotten about, I think the original fitting of both glasses we rush jobs and not done properly, they have been promised to me by Friday... but I was also told that last week. Now my son has to wear his prescription sunglasses to school. As you can imagine I am now wary to send his sunglasses back to be fixed...Is it normal for glasses to take 3 weeks to fix, even if they have to start from scratch???