Have used Gexa Energy since the AA Promo came out a few years ago.
Waited about three billing cycles before first miles posted. Since then, miles post each month.
Tip: Keep an eye on your KWH rate...as many programs on various electric providers in Texas have adjustable KWH rates, when your rate gets to say 11, 12...etc......You can always call your provider and ask if they will lower your rate. Just like you'd do for your credit card interest rate. They want to retain customers and keep folks happy..
Cheers