Yes it is true.... do not pay! I got calls from these criminals and do not pay them at all. For H1B and or L1 category visas do not need any medical check ups!
that adress is
S Post Office
U.S. Postal Service
Address:2202 S Cockrell Hill Rd
Dallas Texas 75211 TX
Phone: (214) 339-xxxx
Click For Phone Number
Website:UPGRADE