Can I combine two power lines from power company
There are 2 questions here:


Can you convert one panel to a sub panel so that both sides are on the same service


Probably. You should be able to get an electrician to do this. It won't require ripping out any existing wiring and shouldn't be too expensive - though some big (expensive) wire needs to be run between the panels.


Can you connect the wires before the meter to get twice as much service capacity


I don't think so, but anyways this is none of your business. Call the electric company and tell them you want to cancel one service and upgrade the other. They will charge you the same whether they run new wires or not.