I had a similar experience, in that they were highly inappropriate, however this was with a local taxi firm in my home town. I had booked my taxi on my online app on my phone, and the driver can see my number to communicate with me, if he needs to for whatever reason. This has never been something that concerned me.
However, one night a friend and I got a taxi back from a bar, as usual I had booked it on my phone. Anyway, the taxi driver was being a little creepy, but we just ignored him and made minimal conversation, however, he was getting worse and worse, and making really inappropriate comments. We were both pretty glad to get out of the taxi and go home. The following day, I got a text off a number I didn’t have saved in my phone, basically saying he was the taxi driver from last night, and thought I was very attractive and wanted to go for a drink with me. Within about 5 minutes he had text again, and again after that, being generally very creepy. I put a complaint in instantly as taking my number of his booking app and putting it into his own personal phone was at the very least at breech of data protection, not to mention extremely creepy. It was not a pleasant experience and made me feel very anxious about getting taxis alone for a while.