It's ridiculous isn't it, I caught some kids breaking into tmy neighbours house when they were on holiday and called the police. The police phoned me back hours later asking me if I still needed them to come.
Also when I Was pregnant my cousin got attacked in a pub so we left quickly but got followed by this person and 10 others. They started going in different directions, obviously to get in front of us, to perform some sort of ambush. We ran to the police station could see people inside and they wouldnt answer. I had to go to the phone box outside and dial 999 whilst my cousin was getting cornered, they weren't even that fussed that I was 7 months pregnant just when they realised we were getting attacked on the police stations doorstep.
I would write a letter and just ask why noone came to your assistance and MB, it's not in anyones interest to have a pregnant woman working alone, I'd voice your concerns and stop doing it.