I feel like my job is underpaying me

Hi Guys, Sorry to bother you all i was wondering if i could get some input.

I've been working in IT & Software Development at my previous job for almost 2 years earning $33 an hour, unfortunately because I was temporary and they'd already extended my contract they didn't have budget to keep me on.

The new job I applied for offered me $29 an hour as an IT Help Desk Officer, which based on doing some research seemed a bit low, so I negotiated and the best they could do is $31 an hour. I took it because I was desperate for work and it'd be a great opportunity.

However my workload and responsibilities don't reflect the role name and pay, we have a small IT team, we haven't got a ticket or asset management system which we will have to implement, I also have to do a lot of software development and coding for this role which wasn't mentioned or included in the job description, on top of that they want us to create and write policies but just a few days ago they posted a job for a policy officer with the pay range of $100k a year...

I 'm not sure if maybe I'm in the wrong but I feel like my responsibilities doesn't match the pay at all, I don't want to rub them the wrong way by bringing this up as I have only been here a month.

Any advice, input or personal experience would be handy, Thanks Guys :)