You need more leverage than you'll ever get with pump pliers or a wrench.

Instead, clamp the tool (BB cup remover) onto the bike with a long bolt, or using the crank spindle and something on the other side.

Once it's secure, place the tool in a vise and use the frame as the wrench. FYI, it's important that thd tool I'd bolted securely to the frame because there's a tendency to not keep everything square, and you'll tear the cup an/or the tool apart.

You'll also help yourself by soaking the area in penetrating oil for a day or two before trying.

One last note - - - make sure you're turning in the right direction. In some countries both sides have right hand threads, however ISO threading has the right side (chain side) using a LEFT HAND THREAD, so it's possible you've been killing yourself trying to tighten, rather than loosen it.