VUMATEL POP Issue and poor service

I have an issue with Vumatel where when there is load-shedding my link goes down even though on my side everything is up with a UPS, and i have logged numerous calls through BITCO who is my ISP, and the calls keep getting closed with silly reasons, like duplicate call or it is up now, but the problem is it is still not resolved as it only happens during load-shedding, so off course if they check now when there is no load-shedding it will be up, but they should contact me and instead they just close the call as link is up, what poor service and now when i get load-shedding i am still down and cannot work.