Dear Markbud!
check the specification, if it indicated what TIssot "promised" as a accuracy range.
for example: -15 +20 or whatever...
If it is out of range, than you may bring the product back for replacement. If it is in the range...then you are not happy..what I understand..
My PR50 quartz is 1 sec/ 1.5 months... my automatic is 3s/day...
So Im affraid the 2min/week is not the top of tops...
Good luck
Kgeez