After sales service needs serious attention

Our generator was serviced by Anderson generators and when we started using the generator for the 1st time it started leaking oil. We then called back as it has a 3 month warranty as per their website. It has been 3 weeks and no call or technician has come to check the leak out after being told that someone will come out on the 20th of June. I must say the after sales service is much to be desired and non existent.