I have been researching this company to see if I would like to do business with them.
Regarding your complaint, however, most states (and in some federal regulations) allow the sale of real estate securities (which is what your owner-financing arrangement is/was) from the orignal owner to whichever financial institution is interested in buying them.
They do not need permission to secure a credit report, or the purchaser's agreement of the sale in order to close such a deal. Only if the original sales contract between you and the original seller prohibited the sale of the contract might the purchase of it be voidable.
It seems sneaky because they obtained personal information and you now pay them instead of the original seller who was an actual person, someone with a face to do business with, but in truth the original seller was functioning as a bank and was in all liklihood within legal rights of selling the security (although Texas has some funny regulations in place regarding seller financing). Most of the time, no financing data appears on any deed, as it is simply a document of conveyance, and is public information once it is filed with a county clerk or similar office. The original seller would have had to furnish this data to the purchasing company in order for them to assess risk and determine whether they wanted to buy the note.
As an example, with the recent financial meltdown in the country (Thank You Congress), a friend of mine has had - within the past two years - three (3) different lending institutions as owners of his mortgage. The only thing he received was a letter stating that the new owner was so-and-so, and where to send his payments.