I'll take this one since I'm in the trenches every day. Chances are your original loan was interest only. If the loan mod is PITI (incl. taxes and insurance) it could be a great rate/ great term of 40yrs but the payment may not go down much since the new payment includes taxes and insurance.
Another explanation is that you had a somewhat lower rate and the reduction in rate didn't bring down the payment that much.
Often times on the loan mods we do, we may get a 2nd mortgage down from 14% to say 7%, which is great, but if the loan amount is only $70k for example the payment doesn't drop that much.
Those may be two explanations. If you want to dig deeper re: "is there any legal action I can take " there are options.
There are a lot of attorneys working the other side of the street doing "foreclosure defense" since they know all the illegal tricks the lenders, attorneys, judges, courts, etc use to steal someone's property illegally.
For example, not sure if you know this but the lender CANNOT foreclose legally without possession of the original "wet ink" signature note that you signed. Not a copy, the original note.
Judge Boyko (google his name) threw out 14 foreclosure cases in Ohio for failure of the bank to prove up their claim. This is just one example.
I'd bet you a steak dinner your original note was sold at least several times and any foreclosure action would be brought illegally with no standing to do so.
I'm not an attorney, not providing legal advice, but I'm pursuing administrative remedies on 5 mortgages personally based on same facts but outside the court system.
If you go with an attorney, make sure you check them out. They usually charge what a loan mod firm would charge (like ours) which is approx. $2-4k up front then a monthly retainer to hold off the foreclosure for a few years. You are not making a mortgage payment during that time but you are paying the attorney monthly.
Google 'foreclosure defense" and you will find some attys. I can also point you in right direction. Will also share the admin remedies we are personally using outside our business.
You as homeowner have many more rights that you know, but lenders want to keep that under wraps.
Hope that helps.