Third Party In App Purchases Charges

I've been charged for in app purchases $14.99 for the past 5 months and Telus cannot tell me which app this is coming from but they're the ones billing me! Very disappointed in Telus and will be looking for another service provider soon, if this does not get solved. I also checked my payments and subscriptions on Google Play store and there's no subscriptions so I'm not sure where and what this charge is for.