Is My Mobile Service Provider (AirCel) Trying to Fool Me [Only Indians Answer Please]?

I've had my phone no. previously registered to the DND service (on the NCPR). About 2 weeks ago, all of a sudden I started receiving a lot of spam SMS and I checked the TRAI site and found that my mobile number had been unregistered. When I contacted customer care they told me that when I register for the first time, it only stays valid for 1 year and then automatically gets unregistered and I have to re-register myself to activate DND again. Is this true or not?

Next, question #2. After I re-registered via 1909 and received my registration no., 7 days have passed (today is the 8th day). Today I went to complain about how spam SMSs have still not stopped, and they said it's actually 7 WORKING days, not just 7 days. I asked them how does this apply to mobile service providers as their offices, customer support etc. work 24x7, they said the technical staff only works 5 days a week so Sat/Sun don't count and asked me to wait for 2 more days before coming back. I came back home but I then noticed that the Government's TRAI site for NCPR says just "7 days" not "7 working days".

So I wanna know if Aircel is telling me the truth about these 2 things or they're just trying to leave me hanging for as long as possible so they don't have to look into it. Somebody with adequate knowledge about the government laws regarding these things please confirm if this is true or not. Thanks.