Product: Mortgage

Hello, I purchased a home to be built from Toll Brothers in XXXX VA. I was informed that I have to get a loan approved by TBI underwriters in order to be able to purchase a home, but I was also told that I can shop other lenders as well later if needed. 
I submitted all my documents to TBI and I had a credit score of over XXXX and so, they quickly approved me and I went ahead with my loan. During 2015 XXXX, while there were discussion around the Fed interest rate hike, I asked TBI if I can get a rate lock for my home and TBI provided me with a rate lock, but with a XXXX % fee if I chose to go with a different lender as a lock breakage fee. 
TBI and Toll both insisted that they are highly competitive in the industry and usually they are 1/8 % lower than most other lenders. They offered me a float down rate lock at 4.625 % with XXXX % penalty if I broke that lock. Since they assured me that when I am within 45 days from my settlement, I can request a new rate if they are lower and they will be able to give me whatever is the in-market rate at that time. Again, in every conversation I had with them, they mentioned that their rates will usually be highly competitive as they work with Toll themselves and their buyers get the best rates. 
I am within 45 days from my settlement now and got quotes from XXXX lenders. XXXX for 3.875 % from XXXX XXXX XXXX XXXX and another for 4 % from XXXX XXXX, both with XXXX points. I sent them this quote and asked for a lower rate. 
TBI came back quoting 4.125 % as my new float down rate on the evening I called them. When I called them the next day morning when I called back for the paperwork, they indicated that the new rate now is 4.25 % and sent me that as my new rate. They indicated that the rates moved since the day before. 
I went back to my lenders and confirmed the rates and I was told by both XXXX XXXX XXXX XXXX and XXXX XXXX that there was no change to the rates that day and XXXX sent me the paperwork for 4 % again. I forwarded that to TBI and to Toll management asking them why they can not match this new rate. 
I am now being told by Toll VP, XXXX XXXX as well as my senior project manager XXXX XXXX that they can not do anything to what TBI has offered and indicated that either I pay 4.25 % or go with the different lender who offered 4 % and pay TBI/Toll the XXXX % lock breakage fee. 
TBI is now insisting that Toll is the one charging this fee and not them and is asking me to talk to Toll. Toll management on the other hand is insisting that the agreement was with TBI and that I have to deal with TBI themselves. 
They keep pointing fingers at each other and now Toll VP has indicated in an email to me that I have to pay this fine if I go with a different lender or accept a higher interest rate. 
I think this is a bait and switch tactic from TBI/Toll and now demanding their buyer to payup one way or the other. 
I am requesting ConsumerFinance.gov team to help me with this issue and tell me if this is a valid practice from Toll/TBI or if this is a unethical or fraudulent practice. Looking for any guidance or advice on this issue as XXXX % is a huge amount considering that I am buying a XXXX home from them. 
Thanks.