Irctc — seat confirmation on computer / off loaded by tc at panvel

I had booked my ticket bearing PNR NO - [protected] in my name Mrs Juliet Sequeria for 12133 Man galore express CI-3A AND wait listed Showing no 6 & before Departure we checked it on line and saw as RAC COACH B3 SEAT 63 And On My Boarding the train in thane the ticket checker said that I was wrong and that I have no confirmation on the same I was of loaded with my 5 year son in panvel. I had to under go lot of harassment. I, Want to know the following 1, how did the situation change in 2 hours of the chart 2, what should I do in this matter and where do I approach and who should I approach