Improve score from 570 to 650 in 2 weeks

I'd recommend checking out Dcummins on YouTube. He made two video's about 1) his journey from 430 to 710 and 2) his advice on scoring 700+ in the shortest amount of time. Though your goal is a bit different (scoring 650 in two weeks), I'd reckon you can still use his advice to some extent.

His recommendations:
1. Only work on one topic per sub-section per area. This allows you to tailor your studying to the areas that you haven't fully mastered yet*.
- Example: topic: Weaken the Argument; sub-section: Critical-Reasoning; area: Verbal.

*This advice is focused on the Verbal section. For the Quant version, he recommends using Target Test Prep (or at least the Trial version). This costs 1$ for a 7-day trial, but this is totally up to you to choose that. Given your two-week timeframe, you might consider doing this.

2. Streak method: train yourself in a particular topic using the following approach**:
- Level 1: Complete a consecutive streak of 10-15 correct sub-600 questions. Once you've done this, move on to Level 2;
- Level 2: Complete a consecutive streak of 10-15 correct 600-700 questions. Optionally, move on to Level 3;
- (Optional) Level 3: Complete a consecutive streak of 10-15 correct 700+ questions.

You have to be very rigid about the aforementioned approach. If you do not complete a streak (e.g. scoring 9 out of 10), you have repeat the whole streak. The idea behind this approach is that you cannot advance to the next level before you've learnt what you needed to learn.

**You can find the question banks on GMATclub. If you click on GMAT (see the black bar on the top-left of the screen), you can find the 'Practice Question Banks' button under 'Self Prep' menu. Note: as pointed out by Dcummins, the questions have varying quality. He uses the following tier-system to select questions:
- Tier 1 (Best): Source - GMAC / Target Test Prep;
- Tier 2 (Good): Source - Veritas / Manhattan Prep;
- Tier 3 (Proceed with caution): Source - The Princeton Review.

3.
- Create flashcards for questions that you've gotten wrong. You can create flashcards manually or use an app (e.g. Anki) to do so;
- If you make a mistake on one of the questions that you've found in the question bank, use the 'Error Log' functionality of GMATclub. That way, you'll have an overview of the questions that you got wrong. You can use that as a basis to learn (or strengthen) concepts that you haven't fully mastered yet.

Hope this helps.