Plumbing problem; reverse course.?

If you are on a pressurized sewer system rather than traditional gravity drained they may have been servicing the mainline & caused a backup. You may also be sharing a sewer trunk line with another residence before it dumps into the main utility line. Either way, the only way to prevent a recurrence is to install a "check" valve between your residence & the main service. A check valve is designed to allow flow out but not back in. Something like this would definitely need to be handled by a professional. If you live in an apartment or duplex they most likely have the mainline installed incorrectly. In any case if you rent, call the landlord. If you own, call a plumber. This is way above DIY.