Basal cell carcinoma left for ten years

I’ve been unaware I had bcc on my face for over ten years. When it first appeared I was fast tracked due to being pregnant and was told that it wasn’t a concern, fast forward to now I decided to go to a private clinic to have the lump removed via laser for my self esteem. It was there and then I was told it was in fact bcc and that my options were to go back on the nhs and wait for the people who got it wrong all those years ago or have surgery removed in the private clinic that day. I decided to go ahead and have it removed. Two consultants did confirm their suspicions before I went ahead and explained everything to me. How could they have got it so wrong years ago? I feel angry and let down. Would it have caused any long term damage due to how long it was on my face for? 

I currently have 11 stitches and so self conscious that I’ll be left with such a big scar.