Travelling from Brussels to Ghent on 7 Dec, my wife and I arrived at Brussels Centraal with two heavy cases at about 1150 and made our way to platform 4 for the 1159 train. One or two minutes before it was due to depart, we were told it would leave from P2. We needed to take a lift up and a lift down to reach P2 and arrived just as it was leaving. The man on the platform said not to worry as there would be another fast train in 15 minutes. A stopping train arrived at 1211 and we tried to get on it but we couldn't as the doors of the rear carriages were closed (despite passengers for an intermediate station being told to join the last 4 carriages). My wife is not very mobile so we decided to wait for the 1216 fast train instead of running down the platform. Two minutes later it was announced that the 1216 would depart from P4 instead of P2 and again we did not have time to rush across. By this stage we had missed three trains to Ghent. So we stayed on P2 and eventually caught the 1227 which ran over 10 mins late. Is there no communication between NMBS signalmen and station staff? It is totally unacceptable to give just one or two minutes notification of platform changes. We are old people who cannot run up and down stairs and need to use lifts. I suppose we were fortunate that there is a reasonably frequent service to Ghent so we only had to wait 50 minutes in total! It could have been several hours if we had been going further. On our return journey, we ventured to the far (north) end of P11 at Brussels Zuid in order to use the lift. When it arrived and the doors opened, we startled an amorous couple about seemingly to prepare for some horizontal recreation. Obviously the lift is not well used. I was not sure whether she was a lady of the night or not, but I thought the red light district was now around Brussels Nord and Schaerbeek rather than Brussels Zuid.