Caller: Amazon they said they were from Zoho Assist

They wanted me to down load zoho assist app on my mobile in order to cancel my subscription or i was to be charged $100:00 dollar's.
i was suspicious and down loaded the app with him telling me what to do Hence when i knew it was a scam i was trying to report it as it came up on the screen to report , he then told me to leave the phone and go and have a cup of tea.... Yeh right...... and he would ring me back .
I deleted the app straight away and blocked the number i am now receiving continuous calls from different numbers with no messages