Flipkart — delay in product delivery

Address:

Vijayawada, Vijayawada, Krishna, Andhra Pradesh, 520010

Sir, i have orde RPM fitnees tredmill on 19 may.its shown delivary date as 4th june and change delivary to 7th, 10th & 13th june continuously.they not haveing having proper delivary data.they are mot aware of wish master or any other delivary detail.the order is also not able to cancel.
What have to ???