I'm having the same issue, but I don’t have any pets in my household. I have Eco installed and upgraded those parts, and my bill was 72 in green, meaning I was supposedly making money from utilities. But no matter how I try to pay through the computer, phone, or even having the physical bill in my Sim’s inventory, my Sim goes through the motions of paying, yet nothing happens. I’ve restarted everything and moved my household into a new house, but nothing helps. Now, all the power is shut off, and it's winter, so I guess my Sims are just going to freeze? There seems to be no way to pay the bills at all, making this game a dead end.
I have found no solution, so I just had to end that game and start a new household. Then just waiting for the next bug to ruin my fun. How can EA just suck so hard? They are really destroying a lifelong gameplay for me. Never seen so many issues since they came in.