Confusedtax82

Hi, Received this notice your Medical insurance has been increased from £201 to £842 your Other items has been increased from £37 to £40 we estimate you have underpaid £68 tax this year But I'm a little confused buy it all, firstly my employer benefits me private medical and I pay an additional monthly premium for my wife. She did recently receive medical care which she paid the excess on. Is that where the £842 comes from and every time we use the private medical I will have to pay additional tax? Secondly it's a £68 deficit, but my PAYE went up £30 this month, surely I should be allowed to clear the remainder rather than pay £30 additional until April? Apologies for all the questions, it's just very confusing.