Welcome to the forums!
I'd suggest reading the following:
Common Abbreviations
Credit Scoring 101 - great for knowing what is in your credit score and to see how your score is impacted.
What Steps Do I Take - great for learning the repair process.
and Example letters - PFDs, GWs, DVs, etc.
I always write as if I had that on my CRs. If I had that, then the first thing I would do is check to see if my state's SOL expired. SOL is the time frame a creditor has to sue you for the debt. They claim you owe $3800 and if you do anything to try to fix your credit or letters to Dell or the CA, you could get sued. Once they try to sue, it'll be harder to negotiate a payment settlement since they'll want the full amount. So, if SOL has expired, then don't sweat it at all. If inside SOL, make sure you have the $$$ to PIF if you had to before doing anything. SOL usually starts from the time it first went delinquent and never recovered (DOFD). Your report info doesn't show this, but if you pull your reports directly from the CRAs (pull for free from annualcreditreport.com if you haven't done so) you'll find DOFD. In some states, SOL can be reset if you make a payment, so you would need to look at your state statutes to see if that's the case. In other states, SOL can be reset if you admit to the debt (mostly in writing).
If out of SOL or you have the $$$ to PIF, then I would contact Dell and ask them if they own the debt. If they do, then the CA no longer matters, though I would continue the payment agreement until you work out something with Dell. Chances are they own the debt because they are reporting a balance and the CA isn't reporting.
I would then look at my other CC-revolving accounts on my CR and figure out via myFICO reports if this Dell account factors into utilization. If it did and if I had the $$$ to PIF, then I would PIF. If this is your only CC CO, then you'd see a large gain in your FICO scores. I would then send them GW letters asking them to remove any lates and/or CO references.
If this didn't factor into utilization, and if I didn't need the history, then I would send a PFD. If they agree, then pay it and they'll delete. If I needed the history, then I would PIF and then send them GWs for the reason mentioned above. To tell if you need the history, look at the date opened and figure out how many years it has been opened. Look at your AAoA. If the age of this TL is much older than your AAoA or even your oldest, then I wouldn't want it deleted because you lose the length of history. If deleted, your AAoA could take a hit along with your score.
There's a lot of what if's here. Hope it wasn't too confusing.
Creditors can charge interest and fees long after you stop paying. My DW had a CapOne account CO'd. The CO balance was $250, but in time, the fees and interest took the balance owed to $750. By the time they sold the debt, there was $15-$20 in additional interest each month.
The names are unimportant. It is the same debt. Dell did financing through CIT. CIT went mostly belly up and Web bank took over.
Dell likely contracted ER Solutions to collect. Paying them through an arrangement is never good, but if in it, then continue until you can PIF or get a PFD accepted by Dell. If you PIF, pay Dell, not the CA. Also make sure Dell is reflecting those payments or even ask for an accounting from Dell to confirm that you are getting credit for that.
