They're not trying to be mean, they're trying to help your fish. If you keep all of those in there they will die. And soon plus they will get stunted which will hurt the fish. As for the pleco, IMO they turn ugly when they get older. Return everything and get some shrimp and some small nano fish. They are very lively and won't be hurt by that tank size. Plus you won't have to do daily changes multiple times a day as you would have to do in the tank you have now. This may be harsh and a little mean but it's the truth and we're just trying to help you and the fish out.