It's hard to say the exact problem but with only one roll left you can't do much experimenting. Certainly different films can be more sensitive to certain processing problems. Would you say the images have a pink/magenta cast or is it only obvious in the clear areas? Increasing the wash after the first dev might help or the colour dev might be a little under strength.

If it was me though, I'd get the last roll processed at a lab you can trust and if that had a cast you'd be on firmer ground in claiming replacement films from the seller. To be honest, I doubt a bad batch of film and if it had been badly stored or heat damaged I'd expect the colour fogging to be patchy.

It's worth saying that the results I've seen from the 'Made in Japan' Precisia have been very good, especially considering how reasonable the price is, just wish they made a 120 version.