Thrush

Any moms who babies have thrush and it won't go away . We've been treating it for 4 weeks now and the spots disappeared but as soon a we complete the meds it comes back . I'm becoming frustrated as my provider says nystatin is the only way to cure it , but it's clearly not helping . fyi we are formula feeding only and I sanitize her pacifiers and bottles daily . Yet to mention after each dose of meds I give her a new pacifier .