Bad service

Had good signal for better part of 10 months; then signal started dropping intermittently and for longer periods at a time. Had technician out and he suggested router be replaced- company refuses to do that - they claim it is the LTE tower dropping signals. Data usage cannot be declared and is unfathomably high. No one can supply information about where data is used. Waited almost 24 hours for top-up and then still didn't register- technician found problem with router.