Yeah, I don't recall personally hearing those two strung together like that, but we definitely say them individually. I was surprised learning that not every English speaking country says 'ta' as a short version of 'thanks'.
This happened to me in Brisbane, as said many years ago, 1980, maybe it is (was) a regional (Queensland) thing, but definitely, while I remember perfectly the first time I heard it because it struck me, it wasn't the "only" time I experienced it.
