Spark Energy Doubled rate and tripled bill Houston Texas

Spark bought my account and probably thousands more from Verde Energy in 2018.  They sent me a nice welcome letter, assured me nothing would change etc.  I was under contract rates and I did know my contract renewal was coming soon.

We use an auto bill pay system, I get a email of ammount due and que the bank to issue the payment so I don't see the bill.  I would have to go on line and look if I thought something was wrong.....but if it's normal, I just pay.

In May my bill suddenly doubled so I took a look.  The rate had doubled and my contract had expired so I call Spark.  The CSR tells me yep, contract price is gone and your paying the rates of last resort / no provider, sorry.  Oh BTW we warned you.  

Also since the contract expired during the billing cycle they retro charged the hammer rate back to the beginning of the cycle. Anything to gouge me and assure I would leave. ( Which I did )

So during the exit period over 2 cycles I used 2342 KW that should have been at .09 cpkw or about $211 and my exit bill was $514.70.

Why would you buy an account and then shaft the owner causing loss of revenue?  Why even bother to buy the account in the first place?   One can only assume that Spark was after a industrial customer / other account and had to take some residentials to get it

Looks like a grand slam to me !