insurance

I want to start delivering for a local indian, it's only a friday 5-8 usually make around £50/60 I've only found out today I'll need delivery insurance but Zego want £400 a month and my current insurers want £150 extra. Anybody know of any place cheaper? live in a small town so it's not a lot of miles I cover but the least amount of miles I can ask for is 1000 a year. Any help the stress of being stopped is making it not worth it