Perhaps you can refinance? Lots of banks offer no-fee refinances. I used Cash Call (not that they have an amazing reputation) but they did a good job with my refi.
... and then it's very likely that you will end up back with Wells Fargo, since they are one of the few banks that service mortgages. Most finance companies sell your loan shortly after originating it.
Citibank tends to keep the mortgage servicing to themselves. They might sell it to fannie mae or similar but you still deal with them as far as payments go.
Yep, happened to me -- had a mortgage with WF, refinanced through a broker and had a mortgage at another bank, then 6 weeks later, got a notice saying that WF bought my mortgage, so I was back with WF.